Print a net, cut it out, and fold it into a cube. Twenty minutes with scissors teaches more than a term of worksheets.
Cube nets are the question type children find most mysterious, because they are being asked to do something in their head that they have never once done with their hands.
Why children cannot picture it
Non-verbal and spatial reasoning carry 25% of the marks, and this is the part of it that nothing in primary school touches.
A child looks at a flat cross of six squares and is asked which face ends up opposite which. If they have never folded one, they have no mental model to work from, and no amount of explanation supplies one. That is the whole problem, and it has a physical solution.
Make one. Actually make one
- Print or draw a net of six squares in a cross shape.
- Mark each face with a letter or a symbol, A to F.
- Cut it out and fold it into a cube, taping the edges, so it ends up like a dice.
- Now ask questions of the cube in their hand. Which face is opposite A? Which three faces meet at that corner? If B is on top and C faces you, where is F?
- Unfold it and ask the same questions again about the flat net.
That last step is where the learning lands. The child answers from memory of the object, then sees how the flat pattern predicted it.
The two rules that solve most questions
Once a child has folded one, these stop being abstract.
- Opposite faces are never touching. Two squares that share an edge in the net end up adjacent on the cube, so they cannot be opposite.
- One square apart in a straight line means opposite. In a row of squares, the first and the third fold to opposite faces.
| Two faces in the net are... | On the cube they are | Why |
|---|---|---|
| Sharing an edge | Adjacent, never opposite | The fold puts them at right angles |
| One square apart, in a line | Opposite | The middle square becomes a side between them |
| Diagonal to each other | Adjacent | They meet at a corner once folded |
| Three apart, in a line | Adjacent | The strip wraps right round the cube |
Those two between them identify the three opposite pairs in most nets. Where a net is an awkward shape, fall back on folding it mentally one face at a time, which a child who has done it physically can now actually do.
Fixing the top and the bottom
The harder questions show a folded cube with symbols on the visible faces and ask which net it came from, or the reverse.
The method is to anchor it. Pick one face and decide it is the bottom. Work out what must then be on top, using the opposite pairs. Then place the remaining four around the sides in order, and check each option against that arrangement.
Do not try to rotate the whole cube in your head. Fix one face and build outwards from it, exactly as with rotation questions.
Worth knowing
There are eleven distinct nets of a cube. Not an infinite variety, eleven. A child who has folded several of them stops being surprised by an unfamiliar arrangement, because there are not many to meet.
See our guide to 3D building blocks, the other spatial type, and our free timed spatial section.
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Give them scissors before you give them a worksheet
Cube nets have always been a mystery to students. It is a tricky topic, and the issue is simply that children cannot figure out the content of it, because they have never handled one.
I would teach it in an online lesson first, so they can see the screen sharing while we go through the rules: how to identify opposite sides, how to determine the top and the bottom. But the thing that actually unlocks it comes next. We give them diagrams of cube nets and they cut them out, fold the net into a cube and make a cube out of it, just like a dice.
Then we give them a set of four questions about that particular cube they have built, and they answer using the cube they have in their hands. The visual element always helps. Suddenly they understand what the next two sides means, or what the opposite side means, because they are holding it.
Mushtaque Ahmed, Founder of GrammarPath and Bright Mentors
Frequently asked questions
How do you teach a child to fold a cube net in their head?
Start by folding one with their hands. Print a net of six squares, label each face, cut it out and fold it into a cube like a dice, then ask questions about the cube they are holding before unfolding it and asking the same questions about the flat net.
How do you find opposite faces on a cube net?
Two squares that share an edge in the net end up next to each other on the cube, so they cannot be opposite. Squares one apart in a straight line do fold to opposite faces. Those two rules identify the three opposite pairs in most nets.
How many nets does a cube have?
Eleven distinct nets. That is a useful thing for a child to know, because it means there are not many arrangements to meet, and a child who has folded several stops being thrown by an unfamiliar one.
Why do children find cube net questions so hard?
Because they are asked to do something mentally that they have never done physically. Nothing in primary school involves folding nets, so a child has no mental model to work from, and explanation alone does not supply one.
How do you answer questions showing a folded cube?
Anchor it rather than rotating it mentally. Pick one face and treat it as the bottom, work out what must be on top using the opposite pairs, then place the remaining four around the sides and check each option against that arrangement.